CT image reconstruction with edge-maintaining filtering

摘要

A method is disclosed for reconstructing image data of an examination object from measurement data, wherein the measurement data were captured previously during a relative rotational movement between a radiation source of a computed tomography system and the examination object. Filtered measurement data are calculated from the measurement data. First image data are calculated from the measurement data. Edge information is obtained from the first image data, wherein the edge information, depending on position, specifies strength and direction of edges within the first image data. New measurement data are calculated using the edge information by mixing the measurement data and the filtered measurement data and second image data are calculated from the new measurement data.

主权项

1. A method for reconstructing image data of an examination object from measurement data, the measurement data being data captured during a relative rotational movement between a radiation source of a computed tomography system and the examination object, the method comprising:
calculating filtered measurement data from the measurement data; calculating first image data from the measurement data; obtaining edge information from the first image data, wherein the edge information, depending on position, specifies a direction of edges within the first image data; calculating, for every pixel in the first image data and relating to a respective pixel for each ray from the radiation source through the respective pixel to a detector element, new measurement data using the edge information by mixing the measurement data and the filtered measurement data using a weighting factor, the weighting factor containing the edge information and information relating to the direction of the respective ray; and calculating second image data from the new measurement data.